Citing a WWE representative, TMZ Sports reported Monday that Flair is being prepared for surgery. It’s not clear which procedure the 68-year-old WWE legend will undergo. Pro Wrestling Sheet reported Saturday that Flair, 68, was admitted to a hospital with heart-related issues, CBS New York reports. The hospital is in Atlanta, where Flair lives, PW Insider reported.

On Sunday night, Melinda Morris Zanoni, CEO of Legacy Talent, which represents Flair, tweeted asking for prayers from Flair’s fans and friends after he was hospitalized with “some tough medical issues” over the weekend.

On Saturday, Zanoni downplayed Flair’s visit to the hospital, tweeting that he was undergoing routine monitoring and there was no reason to panic. But a day later, the situation sounded more dire.

One of pro wrestling’s most recognizable figures, Flair was a 16-time world champion whose career spanned for nearly 40 years. He was inducted into the WWE Hall of Fame twice, once for his own career and once as a member of the Four Horsemen, the group that also included Arn Anderson, Ole Anderson and Tully Blanchard.